The present invention relates generally to weapon release systems, and more particularly, to a constrained store release system which has the capability of accomodating stores (e.g., bombs or missiles) of different sizes and shapes.
Most modern strike aircraft are designed to carry, release, and deliver on target a wide variety of weapons, such as bombs and missiles. The weapons carried and released in this manner are generally referred to as "stores". However, it will be appreciated by those skilled in the pertinent art that the term "stores" is not limited to weapons, but rather, is a generic term which broadly encompasses any item of cargo which is carried, released and delivered from the aircraft.
In this connection, modern strike aircraft are provided with suspension and release equipment (S&RE.) which is designed to carry the stores and to safely separate the stores from the aircraft. The S&RE typically comprise pyrotechnic-driven short-stroke pistons which are designed to rapidly accelerate the weapon through the adverse flow field close to the vehicle. These pistons impart only a point contact force to the stores and no facility is provided for controlling the stores during weapon release.
As strike aircraft have continued to fly faster and with greater maneuverability, the environment surrounding the aircraft has become more severe, thereby increasing the risk of store-to-store and/or store-to-aircraft collisions, and thereby reducing the delivery accuracy due to lateral dispersion. For certain types of stores, the employment envelope of the aircraft has been placarded to reduce the risk of store-to-store collisions and to increase delivery accuracy, but this measure has resulted in reduced survivability of the aircraft.
Several techniques have been developed to improve weapon separation from the aircraft and to increase delivery accuracy without the need to placard the employment envelope. One early technique entailed actively controlling the orientation of the stores and motion thereof during ejection in all three major axes, e.g., by physically retaining the store on a scissors-type carriage mechanism throughout the ejection stroke. This technique has been termed "controlled release". Another technique, dubbed "constrained release", entails preventing motion of the store throughout the ejection stroke, but only in one or two major axes, as opposed to all three major axes. For example, a device constructed to react against yaw moment and side loads during ejection would prevent or constrain motion in the yaw axis.
It has been demonstrated that a yaw axis constrained release system, especially when coupled with increased vertical end-of-stroke (VEOS) velocity and increased stroke length of the ejection piston, results in (1) a reduction in the store yaw angle throughout the ejection cycle, thereby resulting in a commensurate reduction in the cargo bay width for internally carried stores; (2) an improvement in the separation distance between the store and the aircraft during ejection (i.e., increased store-to-aircraft clearance); and, (3) a reduction in system-induced lateral dispersion, and thus, improved delivery accuracy. For internal carriage, such a yaw axis constrained release system affords substantial S&RE equipment size and weight reduction, as well as a reduction in the size of the cargo bay for a given set of stores. Further, since constrained release facilitates better weapon separation, this enables closer spacing of stores, additional flexibility in weapon station location, and a reduction in the number of test flights required to clear a store for an aircraft.
Several types of modern missile launchers, such as the LAU-106 and the LAU-116, incorporate a yaw axis constrained missile release system like the one depicted in FIG. 1. As can be seen, this yaw axis constrained missile release system includes a wrap-around yoke swaybrace which is driven by an ejector piston 22 from a stowed position to an ejection position to effect weapon release.
However, a significant limitation of the yaw axis constrained missile release system depicted in FIG. 1 is that the yoked swaybrace 20 is sized and configured to conform closely to the missile 24 which is nested therein, and thus, it is only suitable for use with a particular type of store (e.g., an air-to-air missile) having a particular store diameter.
Based on the above and foregoing, there presently exists a need in the art for a constrained store release system which overcomes the significant limitation of the above-described yaw axis constrained missile release system depicted in FIG. 1. The present invention fulfills this need in the art.